| 21. | The miners maintained that it was a natural placer deposit that belonged to the discoverers under Spanish law.
|
| 22. | Besides placer deposits of gold, and gold bearing quartz in weathered rock, gold also occurs in quartz veins.
|
| 23. | Native nickel-iron alloys with Ni 3 Fe to Ni 2 Fe occur as placer deposits derived from ultramafic rocks.
|
| 24. | They were also extensively used in hydraulic mining and working placer deposits for gold, tin and other heavy minerals.
|
| 25. | Initially, discoveries centred on placer deposits, which did not uncover the enormous primary deposits in the form of kimberlite pipes.
|
| 26. | After the placer deposits were exhausted, mining turned to the lode deposits that were the source of the placer gold.
|
| 27. | Panning for gold can be used to locate the parent gold veins which are the source of most placer deposits.
|
| 28. | The location of most Yogo sapphires within igneous rock rather than from alluvial placer deposits requires difficult hard rock mining.
|
| 29. | Over 3.6 million ounces of gold have been recovered from the Nome district, almost all of it from placer deposits.
|
| 30. | They are formed by accumulation of such heavy minerals within beach systems, and are a type of " placer deposits ".
|